1. Field of the Invention
This invention relates to the sad, daily reality that people, upon awakening, often turn on the hot water in the lavatory or shower and allow the cool lead water to run down the drain until the water is hot enough for use. Generally, this is water which has been standing in the delivery piping overnight and has cooled to ambient temperature. This problematic scenario is not only a morning ritual, but often occurs prior to an evening rite resulting from daytime cooling of the water due to non-use. The procedure causes the cooled water in the lines to be wasted at a rate of up to ten gallons a day per household. Statistics from 2005 research by the California Energy Commission show that US residents spent $10 billion a year waiting for hot water.
Some households, mostly in recently built homes, spend substantial initial and operating costs for electric powered recirculation pumps and dual piping within the hot water heating systems which keep hot water available for immediate use at the point of demand. Experts in the field agree that initial construction and materials and recurring operational and maintenance costs, along with energy costs, far outweigh the value of any water saved. Others, who are mindful of the occurring waste, use basic, often impractical, tedious trapping and storage methods which demand much dedicated, attention, time and effort.
The problem of the squandering of a very precious commodity is persistent and growing throughout and requires instant attention and resolution.
2. Description of Prior Art
There exist three-way fixed thermal diverter-valves, but these are generally for commercial and industrial use and are not conveniently user-friendly or conveniently operable. Existing three way thermal diverters do not shut off automatically and are still capable of wasting water if not attended to.
Review of prior art shows that the present invention, in its simplicity, differs substantially from several currently known prior art devices and systems aimed at resolving the same problem. In many cases, devises and systems in other prior art are generally complicated, incorporate many components and operational activity and in many cases require electrical power, controls and electronic monitoring. It is not apparent that any such device exists that does not require power or that is readily accessible to existing water systems for installation by home or facility owners.
Powered recirculation pump systems are generally installed in new homes by plumbers and mechanical contractors at significant expense. In contrast, the duality of the present invention is without doubt apparent in that it can be easily retrofitted in existing homes by minimally skilled homeowners at a very affordable cost. As a convenient alternative, the device can also be readily installed in new buildings with very little additional construction costs.
The Mutlund® Hot water demand system, (U.S. Pat. Nos. 5,277,219; 5,042,524; 4,945,942) requires the existence of circulating lines in order to be to installed in existing homes; adds piping, controllers, pumps, sensors and valves to the system at notable cost.
U.S. Pat. No. 7,934,663, Willsford et al. relates to a recovery system for standing water between the hot water heater and the shower and includes piping, a suction device or pump, mixer valves, storage tank, control valves, a Venturi (air streaming) device and extensive added piping. It is claimed that the system can be installed in new construction or retrofitted to existing conditions. With all the components involved, it likely that retrofit will be more difficult and expensive than that claim would anticipate.
The said recovery system's diversion valve consists of a sealed body with one inlet and two outlets and two chambers which are separated by a ceramic plate operated by a thermostatic wax filled cylinder with a piston which slides the plate over a matching fixed plate. Both plates have matching holes which direct water flow based on the sliding plate's position as influenced by the thermostatic piston. The valve also incorporates a diaphragm valve to direct the water flow in and out of the chambers. The diaphragm valve and piston work against a compression spring. All of the valve's components are subjected to exist submersed in the water flow and thus are exposed to being jammed by particles of residue within a less than pure water supply. Further, the valve has a small bypass opening between chambers which would likely allow slow constant flow to the storage component of the system where water waste could occur upon the tank's overflow. From the text of the invention claims, operation of the valve is dependent on opening the mixer valve at the lavatory which indicates that some cool water from the mixer will spill down the drain until the warm water arrives. Upon arrival of the hot water it seems that the mixer valve shut off is not automatic and needs to be turned off or further water waste will occur.
U.S. Pat. No. 7,707,665 B1, K. Hong, embodies a water conservation apparatus that incorporates a series of pipes and timed valves into a bellows reservoir for timely release into the cold water source by use of a water pump, regulators, valves and timing devices requiring electrical power supply. The disclosure of the invention suggests that water flow is diverted to the storage bellows by opening and closing up to 6 valves manually or electronically. There is no size scale indicated on the invention drawings so it is likely that the piping and valves are all indicated to be installed on or within the shower wall. The bellows reservoir is purported to hold as much as 10 gallons, hence weighing over 82 pounds and being 1.35 cubic ft. in size. Unless re-installing all piping within the wall and the reservoir mounted well up above the shower, much of the shower space is taken up by the system. Demolition, added piping, rebuilding and addition of power suggest that this installation can be quite expensive.
In the spirit of the present invention which is mounted at the inlet to the lavatory in the site of the shower, Patent Application Publication No. us 2009/0095356 A1, Greenthal et al. proposes a unitary valve block set between the faucet assembly and the hot and cold water inlet and connected to an accumulator with a pressure membrane which causes backpressure on the coldwater line once the accumulator begins to fill. This changes flow paths within the valve block which incorporates elements that are precisely sized to anticipated pressures and calculated flow rates, and consist of two large pressure actuated pistons and two in-line smaller pressure actuated pistons for each hot and cold water inlet, three pressure actuated check valves working against the pistons and ambient pressure along with a temperature actuated piston valve assembly which reacts to the introduction of hot water to the assembly and incorporates several pressure relief valves and O-ring seals.
Unlike the present invention, the valve block has many parts, seals, cavities and flow paths which suggest that manufacture of the unit will be complicated and expensive. Also the assembly's interior and parts are all in contact with the water and thus are disposed to being jammed by particles of residue within a less than pure water supply. This unit also seems to loose water upon initiation of the flow cycle.
U.S. Pat. No. 6,588,377, Leary et al., offers a diversion valve and a storage module mounted in the cavity below the lavatory. The system is connected at the hot water inlet to the lavatory faucet as is the case in the present invention. The system converts energy by routing unused hot water back to the water heater between uses. It uses a capture and hold tank which is partially filled with phase change gas. Pressure sensors open or close the diverter valve moving cold water into the upper chamber of the tank. The tank gas is expanded or retracted via use of a heat exchanger using a processor controlling temperature and pressure changes. The change in pressure forces water back to the water heater via a dedicated line. Indications from the configuration of the system are that a second tank is anticipated to capture excess water and return it to the existing water heater, hence adding piping to the system.
U.S. Pat. No. 5,603,344, Hall Jr., defines an apparatus for recovery of cooled water uses an interior hydraulic motor and adjustable thermostatic control to pump the cooled water to a cold water pipe leading to storage. Pumping begins when the hot tap is turned on and stops when hot water reaches the apparatus; the cooled water flow is split, a portion moving through the pump and the other portion connecting to the cold water side; an initial 25% flow of water used to accommodate the pumping escapes, saving only the remaining 75% into the cold water system. The unit is self contained and houses both hot and cold water to the faucets. This allows internal transfer of the cooled hot water to the cold water supply. Justification for the water loss rests with the otherwise expensive installation and use of electrical power to the pump. As is the case with other devices, the valve's components are subjected to the water flow, thus are disposed to being jammed by particles of residue within a less than pure water supply.